More than twenty years into the HIV epidemic, the search for an effective HIV vaccine continues. Once a candidate HIV vaccine is demonstrated to be effective in adults, vaccine trials in adolescents can begin. Adolescents will be an important target group because one quarter of new HIV infections are estimated to occur in youth under the age of 21 years. Researchers will need to obtain informed assent from the adolescent and permission from a parent. In order for a trial to be ethical, it is imperative that adolescents who participate in future HIV vaccine trials can adequately comprehend the information that they are presented with prior to making a decision about providing their informed assent. Objective: The objective of this research is to develop a computerized informed assent that can be used by researchers recruiting adolescents 15 to 17 years of age for HIV vaccine trials. The computerized assent will be designed to maximize adolescents'understanding of the critical issues involved in an HIV vaccine trial and to insure that they have a satisfactory appreciation of what they are assenting to. Specific Aims: 1) To better appreciate adolescent understanding of HIV vaccine trial assent information and 2) To develop and evaluate an interactive computerized assent. Methods: Both qualitative and quantitative methods will be used to address the specific aims. For Aim 1, we will conduct eight focus group interviews and eighteen cognitive interviews with 15 to 17 year old adolescents to better appreciate a) their understanding of key features of HIV vaccine trials, b) their understanding of assent form terminology, and c) their preferences for presentation style of a computerized assent. The data will be analyzed using ATLAS.ti software and qualitative content analysis techniques. For Aim 2, a previously developed simplified paper assent form will be converted to a computerized format. Next, we will develop comprehension items for each element of informed assent. Finally, 120 youth between the ages of 15 and 17 years will be randomized to the interactive computerized assent or the simplified paper assent. Efficacy of the two methods of assent will be compared by assessing a) comprehension of assent information and b) participants'appreciation of potential personal consequences of study participation. Impact on public health: A future HIV vaccine is thought to be the only means of eventually stopping the deadly HIV epidemic. Adolescents will be a target group for such a campaign because such a large proportion of HIV infections are contracted during adolescence. Vaccine trials will need to be performed in this age group to insure that a candidate HIV vaccine is effective in adolescents. In order for such trials to be ethical, it is necessary to demonstrate that the assent information provided to adolescents results in satisfactory understanding of the key components of the trial.Once an HIV candidate vaccine is shown to be effective in adults, HIV vaccine trials in adolescents will commence. Adolescents will be an important target group because one quarter of new HIV infections are estimated to occur in youth under the age of 21 years. In order to be ethical, it is imperative that adolescents who participate in future HIV vaccine trials can adequately comprehend the information that they are presented with prior to making a decision about their participation. We propose to develop a computerized assent designed to maximize adolescents'understanding of the critical issues involved in participation in an HIV vaccine trial.